Researchers discuss Pierce's disease findings

CORONADO -- Researchers who are trying to unfold the mystery
behind a bacterial infection that's crippled grapevines from Wine
Country to Napa Valley need to keep each other informed of their
latest findings in order to get a better handle on how to further
combat the disease.

That was the message state, county and local agricultural
representatives gave to about 150 people at the Marriott Hotel in
Coronado on Friday, most who are tasked with finding a way to
combat Pierce's disease. The bacteria, which is spread by the
glassy-winged sharpshooter bug, caused an estimated $14 million in
damage to Temecula vineyards and $40 million in damage statewide
last year.

"(Pierce's disease) is why the world's leading scientific
experts are gathered here," said Bill Lyons Jr., secretary of the
California Department of Food and Agriculture, which organized the
event. "We're heading in the right direction (and) I urge you to
continue your efforts. Clearly research is the answer."

Researchers from across the country, including UC Riverside and
Mississippi State, spent the past three days exchanging information
they've uncovered in their efforts to better understand how
Pierce's disease attacks and kills grapevines. A series of
15-minute seminars were held Wednesday and Thursday, in which
research groups would discuss their findings and host
question-and-answer sessions.

One of those researchers was Raymond Hix, an entomologist at UC
Riverside, who made a presentation on the development of trappings
systems used to capture the sharpshooter. For nearly two years, Hix
and several of his university colleagues have been trapping
sharpshooters in Temecula vineyards in order to get an estimated
count of the number of bugs.

The sharpshooter population was monitored weekly in nearby
citrus and grape crops after about 1,300 acres of vineyards were
initially treated during April and May 2000 with Admire, an
insecticide. That was followed in March and April (2001) by
treating about 269 acres of citrus with Admire and another 319
acres with Baythroid, another insecticide.

During the process, winegrape growers were advised to remove
sick vines. What Hix found was that the sharpshooter population was
significantly reduced in all areas. During the peak periods of each
year for the sharpshooter, which is August, trap catches went from
200 per trap in August 2000 to 10 per trap in August 2001, he
said.

"We are definitely going to do it another year," Hix said. "We
know that we can keep the population low. We are trying to limit
the spread by containing the (sharpshooter)."

Those and other results presented during the three-day event
were well-received by Temecula growers, such as Ben Drake of Drake
Enterprises Inc. of Temecula. Drake, whose firm manages and leases
about 250 acres of vineyards in the region, attended seminars on
Wednesday and Thursday.

"I think there is always some mixed emotions. There were some
projects that were quite successful, some looked good and some you
said, 'What was that?' But that's what we were there for," Drake
said. "It gave everybody a chance to get together and exchange
information."